Power grids, that are power networks for the distribution of electric power from the place of its generation to the different locations where the electric power is to be used, may differ from each other in different regions of the world. Power grids may for example distribute electric power in direct current (DC) form. Modern power grids, however, distribute electrical energy usually by means of alternating current (AC) because of their superior properties for the transmission of electrical power over large distances.
AC power grids further differ in the number of phases used to distribute the energy, as well as in the amplitude and the frequency of each phase signal. In North America for example one-phase power grids are usually used whereas in Europe three phase power grids are usually used to distribute electrical power.
In many applications the electrical power distributed over the grids is not used directly to operate electrical devices. The power first is converted to provide an input power signal required by a particular product. Such products include every device that is operable directly at the public AC power grid, for example power supply units (PSUs) for computers such as servers or personal computers, storage devices and network industry as well as PSUs for telecom infrastructure. But they also include inductive cooking/heating systems or automotive chargers, particularly on-board chargers (OBCs) used in electrically driven cars and other EV (electric vehicles) or HEV (hybrid electric vehicles). Such OBCs charge the high-voltage traction battery used in such vehicles directly from the public AC power grid.
Document US 2011/0080693 discloses a power distribution unit adapted for receiving diversified three- or single-phase power. The unit includes a separable power cord as well as a separable wiring block. The separable power cord is used for receiving electric energy of input power. The separable wiring block is electrically connected with the power cord for providing at least one connection configuration. Accordingly, in order to provide different input configurations, the separable wiring block has to be manually removed and another wiring block has to be manually inserted. Therefore, the housing of the unit must include a removable cover to enable access of the wiring block.
Document US 2013/0072070 A1 discloses another distribution unit (1) including a main body, a first electric connector, and a power input module (2). The power input module is swappable to be accommodated within a receiving part of the main body. The power input module (2) is provided in different variations complying with different utility power specifications of different countries or regions. Again, in order to provide a device to be used in different regions, a part of the device has to be exchanged.
In order to use a particular device throughout two or more regions of the world having different types of power grids, different input configurations of AC power converters are therefore required. According to the prior art, provision of different input configurations is either done by manually or by exchanging certain elements of the power supply unit.
This means that different hardware variants of a specific product or at least a part of it have to be provided such that this product can be used worldwide. Due to these country or region specific variants of a particular product, not only the efforts regarding the logistic are increased but also the efforts regarding the development and the production are increased.